Electrophoresis particle tracking

The most popular method of measuring electrophoretic mobility is micro-electrophoresis. In microelectrophoresis, particles are placed in a closed capillary with electrodes at either end. When an electric field is applied the particles migrate towards the electrode and their velocities are measured. Because the capillary walls are charged the applied electric field will also induce an electro-osmotic flow. However, since the capillary is closed a back pressure creates a net zero flow in the tube (see Fig. 3). The particle velocity is a combination of the electrophoretic motion and the fluid flow. To obtain the true electrophoretic mobility the particles must be tracked along the stationary layer where the fluid velocity is zero. 

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